I've had the same problem. It was supposed to freeze hard a few weeks ago. I cut off the dry seed pods and those that were starting to dry. I put them in a paper bag and kept them in an area where they could naturally dry. Most of those dried and are viable. The ones that were too young became empty shells and split open when I pinched them. I would do that if I were you.
I don't know how tall your plants got, but mine got 6 ft or more and if the freeze had come the entire plant would have been on the ground. Between foot traffic, animal traffic and all I don't think I would have been able to save a single seed.
Just my opinion--I love castor beans! It's a family tradition and it's a chance to grow something tropical in a place where few tropical things grow!
Heidi

Thanks for the response, Heidi, and for the ideas.

I had one large cluster of seeds ripen on the plant a week or so ago and a few isolated ones after that. I saved all of those. Most of the seeds are still on the plant, many large clusters of them, and some of the pods look damaged.

This was a banner year for seeds. I just wish they had formed a little earlier and had had more time to ripen. I have more than enough for my use but was hoping to trade/give away some. I have friends who plant them to deter moles and always appreciate getting a few seeds. I will try your idea of examining each seed to see if it's heavy and has well-defined mottling.

I, too, love the look of the castor bean plant and it's so easy to care for. Mine grew 6 - 7 feet tall this year and had maroon leaves and stalks.

The frost is nipping it slowly, no sudden death yet, so I'm hoping some of the stems are still feeding the seeds. Each morning the leaves are a bit more wilted but only a few look like goners. I guess that will change if the polar vortex comes at the end of the week as predicted. Until then, I'm just going to leave the seeds on the plant and harvest after the big freeze, if it comes. Who knows, we might get lucky on the weather. I doubt it.

Thanks again,
Barbara

I always let mine over winter and harvest as I take the parent down in the Spring. I enjoy the birds taking a rest on old branches. I have never had a problem overwintering plant.